Thermal Vent Lumbar Support helps to provide pain relief and compression for muscle injuries and general lower back dysfunctions, injuries to the lumbar discs and the sacroiliac joint. This product has two flexible internal stays for additional support and adjustable elastic side straps for extra compression. Engineered with MVT Micro Ventilated Thermal Technology. Thermal Vent Supports have a soft thermal lining that captures and retains your natural body heat to help relieve pain. The microventilated, breathable membrane is comfortable against the skin and provides a free flow of air which allows the skin to breath. With unsurpassed quality, these supports provide gentle compression and warmth to help reduce swelling and associated pain as well as promote recovery.